The present invention relates to an apparatus for separating stacked objects and displacing them one at a time or as groups to a treatment location. More particularly this invention concerns a separating conveyor.
In many industrial objects are stacked one atop the other in an upright chute having an open lower outlet positioned above a horizontally extending conveyor provided with a plurality of upstanding seat-forming pushers. The objects are picked off the bottom of the stack, either one at a time or in groups, by the pushers as they pass underneath so as to transport the object(s) that have been picked off downstream to a location where they are, for instance, boxed.
The conveyor typically is formed as one or more parallel belts or chains from which the pushers extend upward. The picked-off objects can rest directly on the conveyor, or move along another surface positioned somewhat above the conveyor and provided with slots through which the pushers project as described in German 1,198,284. Stops may be provided to hold back the stack as the bottom objects are stripped away as described in German 2,930,071.
While such systems are extremely effective, it is often quite difficult to adjust them to accommodate objects or groups of objects of different heights. Thus when the system must be switched over to strip out, for instance, a taller object or a taller group of objects, it is necessary to fit the conveyor with taller pushers and/or change the height of the lateral outlet port of the chute. Either procedure requires that the system be shut down and parts be removed and/or replaced.
It is therefore an object of the present invention to provide an improved sorting or separating conveyor.
Another object is the provision of such an improved conveyor which overcomes the above-given disadvantages, that is which can easily be reset for objects or objects groups of different heights.
An object-sorting system has according to the invention a conveyor having a horizontally extending stretch, a plurality of pushers fixed on and spaced along the conveyor and extending upward from the stretch thereof, and an upright chute adapted to hold a stack of objects and having a downwardly open outlet spaced above an upstream end of the conveyor stretch. An elongated support surface extends horizontally above the stretch and has an upstream end below the outlet port and a downstream end so that the stack of objects in the chute can stand on the support surface. A drive advances the stretch and thereby displaces the pushers downstream past the outlet so that the pushers engage at least a lowermost object of the stack in the chute and move the engaged object(s) downstream along the support surface. In accordance with the invention the support surface can pivot about an axis at the support-surface downstream end and thereby change a vertical spacing between the support-surface upstream end and the outlet port.
Thus with this system when the height of the object or group of objects being picked out of the chute changes, all that need change is the angular position of the support surface. For taller objects or object groups, the surface is pivoted down, and for shorter objects or object groups it is pivoted up. There is no need to change the pushers whose effective length, that is the amount they project past the surface, is determined by the position of this surface.
The support surface according to the invention is formed with longitudinally extending slots along which the pushers pass. In addition the stretch is inclined upward from its upstream end to its downstream end. Thus the pushed objects will be urged by gravity against the pushers which, according to the invention, are spaced apart to define seats having a longitudinal dimension greater than a predetermined maximum object length. Thus the pushers can be permanently mounted on the conveyor which need merely be speeded up a little to work with extremely short objects. There is no need to provide structure defining the leading ends of the object-receiving seats.
The chute in accordance with the invention has telescoping side plates attached to the support surface. In addition it has a closable holding flap controlled with and by the telescoping side plates. Such a flap can bear in an upstream direction on the lower end of the stack in the chute so that it is not entrained by the surface and will only move off when the objects are actually engaged by the pushers and positively entrained.
The support surface can be formed by a longitudinally slotted plate and by one or more belts riding on the plate. In addition the pushers are pivotal on the conveyor between an up position extending transversely thereto and a down position extending generally parallel thereto. A cam arrangement pivots the pushers into the down position except in the stretch. A stationary stop plate extends transversely across the stretch at the downstream end thereof and a boxing apparatus can be provided at the downstream end for removing the objects from the downstream end of the stretch and packaging them.